Just to review the technology, isotemp water heaters use clever coil designs to suck surplus energy from yacht engines. Their exchangers collect engine heat, warm water, and deliver that heated water to chilly crew members. If engine heat isn’t available, an inbuilt immersion heater element takes over. It’s a brilliant design, one that’s been talked about in past articles. Knowing how it works, though, exactly what are they used for?

Equipped With a Safety-Oriented Mixing Valve

Hopefully, the yacht in question is buoyed by smooth waters. Even so, climbing inside a narrow shower cabinet, and everything is narrow on a yacht, a first-time visitor to the boat could become confused by an unfamiliar temperature mixer. Think about a worst-case scenario for a minute. Someone jumps into a shower to freshen up before shore leave, and the lazily rolling craft causes that person to stumble. Jerking the faucet, the water comes out of the shower head as a scaldingly hot stream. And there we have the second reason for installing an Isotemp water heater. You see, as well as being energy efficient, this equipment incorporates a special temperature controlling safety valve. Should a narrow shower cabinet cause problems, the mixing valve automatically regulates the water temperature, thus preventing a nasty burn.

An Ode to Hydronic Radiant Heating

Safe for use as yacht shower heat, the compact cylinders and blocky containers are also rated to function as boat heaters. The energy starts its journey back at the engine. Back here, the heat exchanger partners with the installed immersion heater element to deliver 190°F of hot water, which flows through a radiant heating appliance and is transformed into hot air. Now, with the thermal energy circulating in the cabin air, new options become available. Yes, the little radiant heaters use hydronic power to warm cold crew members. That’s a fairly obvious application. Secondly, the heaters can be redirected and repurposed. For example, instead of using hydronic heating to warm people, it can be employed to dry out wet equipment. Similarly, with the yacht owner perhaps worried about bulkhead mould, a large capacity 25-litre model soon dries out mould-prone boat sections.

And there we have it, the many reasons for fitting an Isotemp water heater don’t begin and end with safe showering, courtesy of that temperature regulating safety valve. On top of this primary feature, larger models can be used to power a hydronic heating system. The radiant heaters warm cabins and crew, they dry wet equipment, and they stop investment-damaging mould colonies from developing on moist surfaces. Made out of 316-grade stainless steel, the toughened Isotemp range is also built to take punishment.